Front calipers on Wilwoods move/expand when applied?

[Erik Beckett]

In another thread I talked about my soft pedal and am basically chalking it up to the small bore master cylinder from Wilwood. We have bled the lines 7-8 times and get no bubbles at all.

But today while bleeding on last time, we noticed the front calipers expand and move out when the brake is applied. The rears don't do it at all, just the fronts. This just doesn't seem right to me or the chassis builder who helped me.

When we pumped the brakes to bled you could see the caliper actually expanding out from the rotor. The brakes work but the peddle is still kinda soft for our liking. He seems to think when the brakes are applied and the caliper actually expands out some the peddle would feel soft.

Again, these are Wilwood 12.19" with your basic 67-69 camaro kit everybody runs.

Any thoughts?

Erik

[Gordz32]

Do you have an adjustable proportioning valve on the car? If so, open it up all the way when ur bleeding the brakes. Also, I really can't believe a caliper would expand outwards, there aluminum and I would think that, that kind of movement would work harden pretty quick and fail. Good luck

[Vegas69]

Seem to remember some movement as well. Are you sure the rotor isn't moving since the wheel isn't bolted on? I am going to be bleeding my again tomorrow since I just added a 2 pound residual valve to the rear.

[Erik Beckett]

No its the actual calipers expanding out since it cant collapse anymore against the rotor it just expands out. This is just the basic Wilwood front kit for a 68 Camaro, so there is nothing special going on here.

Its pretty obvious it does it though. The chassis builder mentioned something about the spacer and the thickness of the rotor and the spacer making it weaker but I am not sure.

I am going to call Wilwood this morning. And yes we have the prop valve wide as per Franks request.

Erik

[Carver67]

I'm not sure if I understand correctly. Is it the body of the caliper that physically expands or is the caliper moving out as a complete unit? if the outer pistons are hitting the rotor first, maybe its pushing the whole caliper out. Maybe the bracket itself is allowing the caliper to move instead of holding it in place.
Good luck.
-mike

[neki67]

I'm not sure if I understand correctly. Is it the body of the caliper that physically expands or is the caliper moving out as a complete unit? if the outer pistons are hitting the rotor first, maybe its pushing the whole caliper out. Maybe the bracket itself is allowing the caliper to move instead of holding it in place.
Good luck.
-mike

It's actually the body of the caliper that's expanding when you push the pedal! I drove my 67 for sometime with Dynalite II's and the pads were even wearing of tilted because of that! As you can imagine I never got the thing stopping very satisfactory.

Please be aware; I only have experience with the billet Dynalite II calipers.

[Vegas69]

Check your center caliper bolts. I just found that my RR caliper Superlite has a problem with bolts that aren't clamping the center of the caliper together. They feel bottomed out or cross threaded. Mine actually bubbled a little during bleeding where the two halfs meet. I have 2200 miles on the car. Calling wilwood Monday.

[JRouche]

Check your center caliper bolts. I just found that my RR caliper Superlite has a problem with bolts that aren't clamping the center of the caliper together. They feel bottomed out or cross threaded. Mine actually bubbled a little during bleeding where the two halfs meet. I have 2200 miles on the car. Calling wilwood Monday.

Thats exactly what I was thinking. The calipers are bolted together. If the bolts are loose then the caliper will separate. But wouldnt you get leaks also??? Definitely a call is in order.. JR

[Vegas69]

I have what I would call a seap. I can put firm pressure on the pedal for 2 minutes and it stays put. However there is just enough fluid to wet your finger. It's getting replaced. Something isn't right with the center bolts. I'm not going to tear it apart and take the chance of eating the cost myself.

[JRouche]

I have what I would call a seap. I can put firm pressure on the pedal for 2 minutes and it stays put. However there is just enough fluid to wet your finger. It's getting replaced. Something isn't right with the center bolts. I'm not going to tear it apart and take the chance of eating the cost myself.

Smart man.. You have obviously been there done that. You have a caliper separating, not flexing. Let Wilwood fix it.. JR